Egyptian Copts gather in cave cathedral ahead of vote on a constitution

An Egyptian flag is waved as thousands of Egyptian Copts attend a Mass in the Cave Cathedral, or St Sama'ans, in the Manshiet Nasser district of Cairo on Dec. 13, 2012, where they prayed for Egypt ahead of the disputed referendum on the new draft constitution slated for Saturday.

An Egyptian flag is waved as thousands of Egyptian Copts attend a Mass in the Cave Cathedral, or St Sama'ans, in the Manshiet Nasser district of Cairo on Dec. 13, 2012, where they prayed for Egypt ahead of the disputed referendum on the new draft constitution slated for Saturday. President Mohammed Morsi and his Islamist allies support the charter while a wide spectrum of liberals, youth groups and others see both the process and the draft as flawed.

Marco Longari / AFP - Getty Images

Egyptian Copts attend a Mass in the Cave Cathedral or St Sama'ans in Cairo on Dec. 13.

Marco Longari / AFP - Getty Images

An Egyptian man prays as thousands of Egyptian Copts attend a Mass in the Cave Cathedral in Cairo on Dec. 13